Human rights groups and Russian lawyers have confirmed that former U.S. intelligence contractor Edward Snowden will hold a meeting at the Moscow airport where he has been confined for three weeks while trying to find a country to grant him asylum.

The head of the Russian office of Amnesty International has said his group received an e-mailed invitation Friday and will attend. Russian news agencies say Human Rights Watch and Transparency International have received invitations as well.

Russian officials say the meeting is set for Friday in the transit zone of the airport.

A Human Rights Watch representative posted an e-mail attributed to Snowden Friday that accused the United States of waging "an unlawful campaign" to deny Snowden's right to seek asylum.

The 30-year-old Snowden leaked secret details of surveillance programs conducted by the clandestine U.S. National Security Agency.

The United States is seeking Snowden's extradition on espionage charges, but Russia has refused to release him to U.S. custody, while urging him to depart for another country.

The leaders of Venezuela, Nicaragua and Bolivia have said they would take in Snowden. But Snowden's exit from Moscow is complicated because the U.S. revoked his passport.

Earlier this week, Snowden explained his disclosure of clandestine American surveillance programs in a newly released segment of a video recorded last month. Britain's Guardian newspaper released the video Tuesday of a June 6 interview conducted in Hong Kong, where Snowden fled last month before flying to Moscow.

Snowden said in the video that he knew the United States would accuse him of espionage in alerting the country's enemies of the surveillance. But he said the United States is also at fault for monitoring the phone records of its citizens and keeping track of Internet connections with possible terrorists.